Influence of Types of Coarse Aggregates on the Coefficient of Thermal Expansion of Concrete

Naik, Tarun R.; Kraus, Rudolph N.; Kumar, Rakesh

doi:10.1061/(asce)mt.1943-5533.0000198

Cited by 39 publications

(15 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is likely to due to the fact that both basalt and granite have similar thermal expansion coefficients. Thermal expansion coefficients for concrete with basalt and granite as coarse aggregate are 9.5 and 9.3 microstrain/°C, respectively …”

Section: Resultsmentioning

confidence: 99%

Specimens size, aggregate size, and aggregate type effect on spalling of concrete in fire

2017

View full text Add to dashboard Cite

SummaryThis paper attempted to isolate variables that govern concrete spalling when exposed to a hydrocarbon fire. The influence of specimen size was investigated by studying 4 specimen sizes consisting of cylinders, columns, and panels. Three aggregate sizes, 7 mm, 14 mm, and 20 mm were used in the concrete mixes to determine their effect on concrete spalling. Influence of aggregate type on concrete spalling was also investigated. Forty-two different specimens were considered in this investigation. Concrete spalling was quantified as nominal spalling depth, which has been presented as a new way of quantifying the degree of concrete spalling. The results indicated that specimen size did have an effect on the spalling of concrete under hydrocarbon fire exposure and that nominal spalling depth of concrete increases as the specimen size increases.Aggregate size effect was evident when the maximum aggregate size increased from 7 mm to 20 mm, and explosive spalling was more severe for specimens with small size aggregates. Specimens with 14-mm aggregate size showed inconsistent results and the spalling behavior witnessed was more random and sporadic. The type of aggregate used has no clear bearing on concrete spalling given both aggregates had similar linear expansion profiles. However, concrete is susceptible to a less known phenomenon termed spalling in fire. Spalling of concrete in fire is the dislodgement of small pieces of concrete up to 50 mm (popping out) from the surface of the concrete, often explosive in nature. If the degree of spalling is significant, the load bearing capacity of the concrete member can be reduced due to (1) reduction in its cross-sectional size, and (2) rapid increase in temperatures of the reinforcement. more predominate when concrete is subjected to hydrocarbon fire due to the rapid heating rise. 5 The moisture content of the specimen has been reported to be a significant factor which governs spalling. 6High levels of moisture content generate the buildup of pore water pressures.A number of key researchers have studied the factors which govern spalling including thermal stresses, pore pressures, thermal dilation, and incompatibility between cement paste and aggregate. 7-10 The "moisture-clog mechanism" due to the buildup of pore water pressures has been widely accepted as the main mechanism causing concrete spalling. 9,[11][12][13][14][15][16][17] Contrary to this, spalling caused by differential thermal gradients within the concrete element has also been widely accepted to explain the spalling phenomenon. crack of critical size and orientation increases with the volume of the specimen. [22][23][24] This is in agreement with Bazant's size effect law (SEL) theory, which states that as the specimen size increases, the compressive strength decreases. 23,25,26 In relation to spalling, the "size effect" phenomenon has a direct effect on the moisture content of the concrete specimen, the rate of in situ heating, and water mass loss. | EXPERIMENTAL PROGRAMMEThe materials used in this investig...

show abstract

Section: Resultsmentioning

confidence: 99%

Specimens size, aggregate size, and aggregate type effect on spalling of concrete in fire

2017

View full text Add to dashboard Cite

show abstract

“…Two-third of the aggregate is composed of coarse aggregates [8]. As a result, coarse aggregate plays an important role in determining the CTE of concrete [9].…”

Section: Coarse Aggregates In Concretementioning

confidence: 99%

“…Based on that conclusion, the test results obtained from the experimental program shown in Table 3 were first grouped according to the coarse aggregate type after that, these test results were compared with the Euro code and ASCE models in separate figures according to the concrete coarse aggregate type as indicated in Figs. 2,3,4,5,6,7,8,9,10. The following paragraphs show the comparison between the CTE obtained from the experimental programs that are shown in Table 3 against CTE obtained from Euro code and ASCE models.…”

Section: Evaluating Available Models For Ctementioning

confidence: 99%

Proposed models for concrete thermal expansion with different aggregate types and saturation conditions

Ghannam

2019

SN Appl. Sci.

View full text Add to dashboard Cite

The Coefficient of thermal expansion (CTE) for concrete is one of the most important parameters that affect the fire performance of concrete. Concrete's coefficient of thermal expansion is controlled by the CTE of each component of the concrete mix, as the coarse aggregates represent the largest portion in the concrete mix, it is considered to have a significant effect on the CTE for concrete. Another factor that affects concrete's CTE significantly is the saturation condition (saturated, partially saturated and oven dried condition). This paper presents reviews for available tests results that have been conducted on the CTE for concrete at elevated temperatures for different aggregates type, these results are used to evaluate the models proposed by ASCE model and Euro Code. The results included the coefficient of thermal expansion for different types of aggregates in different saturation conditions (saturated, partially saturated and oven dried condition). It is found that there is a significant difference between the experimental results and Euro code carbonate model, Euro code siliceous model and ASCE. New models were proposed for predicting CTE of different types of aggregate under different saturation condition. The newly proposed models give better prediction compared to Euro code and ASCE model.

show abstract

“…Some authors have investigated the effects of internal water pressure (Siddiqui and Fowler 2014) or earth pressure (Iskander 2013) on the coefficient of thermal expansion of concrete. This coefficient was established using the micromechanical model (Zhou et al 2012(Zhou et al , 2014 or measured and evaluated (Wang et al 2013) according to the type of coarse aggregates (Naik et al 2011). Theoretical examples of the calculation of measurement thermal stresses in massive hydraulic structures are presented by .…”

Section: Introductionmentioning

confidence: 99%

The Influence of Temperature Change on Crack Openings in a Reinforced Concrete Shell of Pressure Piping at Kruonis Pumped Storage Power Plant

Šadzevičius

Gurskis

Skominas

et al. 2017

EREM

View full text Add to dashboard Cite

Cracks are classified according to their geometry (length, width and depth), statistical parameters (mean and variance of the number of cracks per unit area), crack riskiness for structures, etc. In this paper, crack openings in a reinforced concrete shell of the pressure piping at Kruonis Pumped Storage Power Plant, which appeared due to temperature change, are analysed. Detailed analysis of cracks and deformations due to temperature changes was performed after the evaluation of the technical state of the pipeline. Specific illustrations, calculations and guidance for repair of these deteriorations were offered.

show abstract

Influence of Types of Coarse Aggregates on the Coefficient of Thermal Expansion of Concrete

Cited by 39 publications

References 4 publications

Specimens size, aggregate size, and aggregate type effect on spalling of concrete in fire

Specimens size, aggregate size, and aggregate type effect on spalling of concrete in fire

Proposed models for concrete thermal expansion with different aggregate types and saturation conditions

The Influence of Temperature Change on Crack Openings in a Reinforced Concrete Shell of Pressure Piping at Kruonis Pumped Storage Power Plant

Contact Info

Product

Resources

About